Telephone-exchange system.



A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM.

APPLICATIN FlLED MAY 25| 1916.

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y /m/e/or: A/ben E. undef/ if STATES PATENT @FFQE ALBEN E. LUNDELL, Oi NEU] YORK, N. Y., ASSIGNOR TO VESTERN ELECTRIC CQMFANY, INCORPORATED, OF NEW YRK, N. Y., A CORPORATION OF NEW YORK.

TELEPHNE-EXCHANGE SYSTEM.

Application filed May 25, 1916.

To @ZZ/whom t may concern.'

Be it known that 1, ALBEN E. LUNDELL, a citizen of the United States, residing at New York, in the county of Bronx and State of New York, have invented certain new and useful improvements in Telephone- Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone eX- change systems employing machine switching, and particularly to the type of system shown in U. S. Patent No. 1,168,319, to A. E. Lundell, issued January 18, 1916, and is an improvement upon such system.

The inventionhas to do with a selector circuit such as shown in said patent, and its object is to reduce the time interval between the termination of the directive movement of said selector, under control of the sender, and the seizure of an idle trunk leading to the next selector.

The invention will be best understood when described with reference to the accompanying drawing, which shows only so much of the telephone exchange system of said patent as is necessary for a comprehension of this invention.

The selector' switch is shown diagramnia-tically at T, and, as shown and described in detail in said patent, comprises a brush `carrier 19 having a number of sets of brushes t fixed thereto, one for each section or division of trunk terminals t. rlhese brushes are normally held latched out of operative relation to the sections they serve, and any set may be tripped, as described in said patent, by the corresponding finger on a trip rod G4, which rod is rotated by a trip magnet rlhe set 'tripped depends on the distance the carrier 419 is elevated by shaft 50 before the trip magnet is operated; and, in turn, the distance the carrier is elevated before the trip magnet is Yoperated depends on the number of segments of the A commutator wiped over by brush before the sender S is satisfied, vall as shown and described in said patent. Each division of the panel, served by a set of brushes b, will be subdivided into groups of trunk terminals, the number of which and the number of terminals in a group being optional.

After the trip magnet 228 is operated, the carrier is again elevated, iirst to pick out the desired group under the control of the sender S, land then to hunt therein for Specification of Letters Patent.

`Patented July 2&1, 1917.

Serial No. 99,750.

an idle trunk, independently of the sender. S indicates the sender. 17, 23, 39 indicate springsV of the sequence switch associated with the first selector. 15, 25, 26 indicate the brushes and 111, 27, 37 the terminals of such first selector, which, it will be assumed, has already been set under control of the sender S. The sequence switch springs to the right of the dotted line belong to the secondselector sequence switch 40, which is normally in position 1.

lThe operation of the system will now be described in detail, as by following the operations, it is thought the invention will be most readily understood. After the first selector has been set on' the trunk terminals 111, 27, 37, the following circuit is closed to initiate the brush selecting operation at the second selector: free pole of battery, relay 212, second selector sequence switch contact 11, conductors 12 and 13, terminal 1st, iirst selector brush 15, conductor 16, sequence switch spring 17 of the sequence switch associated with the lirst selector and its lower contact, conductor 18, relay 19, armature and back contact of relay 20, sequence switch spring 21 of the sequence switch controlling the sender, conductor 22, iirst selector sequence switch spring 23 and its top contact, conductor 38, rst selector brush 25, terminal 27, conductor 28, second selector sequence switch contact 29 and its lower contact, to ground. Relay 212, in attracting its right armature, locks itself over conductor 3() and second selector' sequence switch contact 31 to conductor 18, independently of contact 11. ln attracting its left armature, it closes the'following circuit for relay 32: free pole of battery, relay 32, conductor 83, second selector sequence switch contact 34, conductor 35, left armature and front contact of relay 212 to ground. Relay 32, in attracting its left armature, locks itself over conductor 36, terminal 37 and first selector test brush 26 and sequence switch spring 39, to ground at the first selector. In attracting its right armature, it closes the following circuit to move the second selector sequence switch 410 from position 1 to position 2: free pole of battery, sequence switch motor magnet 41, conductors Ll2, 43, second selector sequence switch spring 44E, armature and front contact of relay 32 to ground.

Iny position 2, the following circuit is closed for the magnet 220 to elevate the brush carrier 49: free pole of battery, inagn net 220, conductor 46, second selector sc` quence switch contact 47, conductor 35, lett armature vand front contact of relay 212 to ground. Magnet 220, in attracting itsmarmature 48, forces brush carrier 49 against a constantly rotatingV shaft to elevate the brush carrier 49. Fixed to the upper end of carrier 49 is an arm 53, carry-ing three brushes 54, 55, 56, adapted to wipe over connnutator plates B, A, C, respectively, as shown in detail in the patent 'heretofore mentioned. For each metallic segment oit they commutatofr A passedfover by the brush as the carrier 49 is elevated, a yshunt circuit is vclosed about the stepping relay 19 at the sender. This shunt -cilrcuit may be traced as follows: free pole of battery, re- :lay 2:12, conductor 30 and second selector sequence switch Icontact 31, conductory conductor 13, second-selectcr vseque-nce con tact "61, conductor 62, segment @if commutator' A, brush 55 to ground. Each time this vsl-iunt circuit closed, the relay 19 at the sender is denergized, and when such sender -i's satisfied, the cut-ori:1 relayQO thereat operates, as `shown in detail in the lpate-nt yreferred to. Relay 20, in attracting its far mature, lopens the Circuit of rela-y 212. Re# lay 9.12, in -re'tra'cting its left'armature,'opens the circuit of elevating magnet Q20, 'whereupon the carrier 49 comes to rest with a predeteriniiiedset 'of brushes Z), in operative relation to the corresponding tripping nw ge'ron 'the trip rod 64, -astsho'wn in the pat ent referred to, Thecarrier 49 is held elevated 'by retaining vpawl '65. The retraction of the left `ar`mature olf relay 212 closes the following circuit 4to inove the second selector sequence switch from posi-tion 2 to position ground, left armature and back 'contact of relay "212, second vselector sequence switch vcontact (66, conductors 43, 42, second selector'sequence switch lmotor inag- 'net 41, freepoleof battery. The second se*- lector "sequence switch thus moves from fpo Sition 2 to position 3.

'In position 3, trip magnet '22S is encrgized, which, in attracting its armature, twists `the trip rod 64 to interlock a *ringer on the said rod and-a leveren the holder ci' the predetermined ybrush 'set 5, pthe reN mainin'g` trip fingers passing `through the lineof ytravel'oi their respective vtrip levers to the 'other side thereof, asshown in the patent Lreferred to.y in position 3, Athe tfollowing circuit is closed'to again energizer'elay 212 :V free pole yof battery', relay lQ12, conductor'63, second selectorsequence switch con tact 11, conductors '12 and 13, terminal 511i, brush 15, conductor 16, firsty selector 4sequence switch "spring 17 and itsk bottom contact, relay 19, Varmature and baclrcontact'o'f relay Q0, now again closed, vsender `sequence switch "spring Q1, conductor 22, first selector sequence switch spring E23 and its upper con-- tact, brush 25, terminal 27, conductor 28, second selector sequence switch spring 29 to ground. Relayy 212, yas before, locks itself 'to conductor 13. Relay 212, in attracting lolloivinb circuit to move the -seeuence switch 40 tokposition 4: free pole othatter magnet/41, conductor 42, contact 170, conductor 74, lett 'armature and front contact of lrelay 67 to ground. ,l l

-In position 4, the following 'circuit is closed for the elevating magnet 220: 'free pole of battery, magnet l220, conductors `46 and 72, second selector sequence switch con tact 73, `concliictor 74,' lett armature and front contact of relay vr6'? to ground. The magnet 220, vattr`a ft-ifng` f its armature 48, again li'orces the brush carrier 49 against the constantly rotating shaft 50, to elevate the carrier `@under `controler the "sender, to thc beginning 10i thegroup in which hunting is to vtake p'lfaee. At the beginning of the up` ward movement the selected rset of kbrushes is tripped so as to be in position to wipe `over the vterminals'olf its group. During this elevating movement', 'the brush 'wipes over segments 'of the fcornmutator B. Each rtimel the `'brush 54 I`engages 'one of the segments fot Y coninrutator B, ythe lfollowing shunt lcircuit is Aclosed about the relay 19 at the sender: free pole of battery, relay 212, `its armature and front contact, 'conductor 3,0, second rsef lector sequence switch contact 31, conductors 12 and 18, second selector sequence switch springv 76, `conductor 77, segments' of conimutator B, brush '54 to ground. rThe kstepping relay 19 is-denergiZed/once for each segment @passed "over by the brush 54, and when the 'required `number of operations of thisrelay have ensued 'to satisfy the sender` the Lrelay Q0 thereof is'en'e'rgized vto vopen the `f circuit of 'relay '-212 totlenergize the lelevating -inagnet 220, all as shown in l"the ,patent y referred ito. The arrangement `is such that,

at "this instant, 'thete'stfbrush b" of the released set of brushes lisin'contact with thet'est terminal 2ofith'e first trunk, and 'relay 212,

. in retracting y'its left armature, will, if such trunk is idle, result "in thedenergiaation oi3 relay 67, which, A1n "retracting 'its 'left armature, will bpen the circuit lof the ele-vatwith thebrushes bon the first setjofterniinals t of the'selectedgroup oftrun'ks. Busy trunks 'arethose whose test terminals/" are grounded, as will 'be hereinafter described. Consequently,A when the relay '20 at the sender Vopens 'the circuitof relay E212 at the ying magnet 220 and stop the brush carrier,

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end of group selection, relay 67 will remain energized over a circuit including its right winding, its armature and front contact, sequence switch contact 78, conductor 7 9, test brush b, grounded test terminals t of busy trunks. l/Vhile the test brush 7) is passing between terminals, relay 67 is maintained energized over the following circuit: free pole of battery, left winding of relay 67, conductors 68, 96, sequence switch contact 97, conductor 98, segments of commutator C, brush 56, conductors 99, 100, sequence switch contact 101, conductor 74, left armature and front contact of relay 67 to ground. Relay 67, in remaining energized, maintains closed the circuit of the elevating magnet 220, which continues the movement of the brush carrier 49, in search of an idle trunk. When a trunk is reached whose test terminal t is not grounded, relay 67 will become denergized, and in retracting its left armature, will open the circuit of elevating magnet 220, thus stopping the brush carrier 49 with the brushes Z1', b2, 3 in engagement with the terminals t', t2, 253 respectively, of such idle trunk. The carrier 49 is held elevated by retaining pawl 65. Relay 67, in denergiz ing, closes the Jfollowing circuit to move the second selector sequence switch out of position 4: free pole of battery, second selector sequence switch motor magnet 41, conductors 42, 43, second selector sequence switch contact 80, conductor 81, left armature and back Contact of relay 67 to ground.

f, The sequence switch moves, under control of its contact a, to position 6, where it comes to rest.

1n position 6, the closure of second selector sequence switch springs 82, 83 extends the conductors 13, 28 leading from the sender to the brushes b2, lf, now in engagement with terminals t2, t, from which conductors 84, 85 lead to the next selector to be set.

When all the switches to the connection have been set, under control of the sender S, the first selector sequence switch is moved out of position 11 and into position 12, in which the calling line E is extended through to the called line, and the sender is cut off from the talking leads 16, 38.

Upon the termination of the conversation, the circuit of relay 32 is opened at a preceding switch by the opening of a contact 39 thereat, as shown in the patent mentioned. This relay, in retracting its right armature, closes the following circuit for the second `selector sequence switch motor magnet 41: free pole of battery, magnet 41, conductors 42, 43, second selector sequence switch contact 87, right armature and back contact of relay 32 to ground. The closure of this circuit moves the second selector sequence switch out of position 6, whereupon a circuit is closed through the contact tion the sequence switch comes to rest.

a of the sequence switch, which is closed continuously from 6 to 18, in which poin position 18, the following circuit is closed for a restoring magnet 264: free pole of battery, magnet 264, conductor 89, second selector sequence switch spring 90 and its bottom contact, to ground. This magnet, in attracting its armature 91, withdraws the retaining pawl from the brush carrier 49, and forces the carrier into engagement with a constantly rotating shaft 92, adapted to lower the carrier. When the carrier reaches its normal position and brush 54 engages commutator segment D, the following circuit is closed to drive the sequence switch from position 18 to normal: free pole of battery, magnet 41, conductor 42, sequence switch contact 150, commutator segment D, brush 54 to ground.

The apparatus is now restored and may be used in establishing another connection.

What is claimed is:

1. 1n a telephone exchange system wherein an automatic switch is power-driven under control Aof a sender, the combination with the switch and sender, a continuously operating driving mechanism, trunks terminating in said switch in groups, test terminals therefor, a magnet for operatively connecting said switch to said mechanism to drive the switch, a power control relay adapted when operated to energize said magnet, a. line relay at said switch in circuit with said sender and energized only while said sender is operating, ak circuit for said power control relay closed at a front Contact of said line relay, and a substitute circuit for said control relay including test terminals of busy trunks.

2. In a telephone exchange system wherein an automatic switch is power-driven under control of a sender, the combination with the switch and sender, trunks terminating in said switch in groups, test terminals therefor, a power shaft, a magnet for coupling said switch to said shaft, a power control relay adapted when operated to energize said magnet and having two windings, a line relay at said switch in circuit with said center and energized only while said sender is operating, a circuit including a winding of said power control relay closed at a front contact of said line relay, and a substitute circuit including the other winding of said control relay and test terminals of busy trunks.

3. In a telephone exchange system wherein an automatic switch is power-driven under the control of a sender, the combination with the switch and sender, a continuously moving shaft, trunks terminating in said switch in groups, test terminals therefor, a magnet for coupling said switch to said shaft, a power control relay for said magnet, a line relay at said switch in circuit` With said ksender and energized only When said sender is oper-ating, a circuit for said power control relay including a Contact of Said line relay, and means including said power-control relay ,and circuits including said test terminals for maintaining said magnet energized after the denergization of said line relayif the switchencountersy busy trunks. y 'l0 Y In Witness whereof, I hereunto subscribe my name this 24th day oiiMay, A. D., 1916.

ALBEN E. LNDELL.

Copies of this jaatent may be obtainedk for rvfive cents each, Vby .addressing the Commissioner of Patents,

Washingtomrl). G. 

